Heretofore air boats have been relatively large, using high powered engines to provide sufficient power to drive boats at high speeds. The boat hulls are custom made to fit the drive systems and are heavy and expensive. Steering is affected by having the propeller blast hit a large rudder or rudders to deflect the air and steer the boat. When the engine dies while operating at high speed, or is stopped, as it must be when approaching a dock or other place to permit passengers to disembark, steering of the craft is lost, often resulting in a very hazardous condition. Most accidents involving air boats are caused by loss of directional control. Other air boats cannot stop the propeller when the engine is idling resulting in continuous movement of the boat.